I love this. Having separated obstacles for double time and strings of only obstacles for some syncopation is very elegant and fun to play. Triplets also introduce a fun change and make the obstacles larger than 1 space extra interesting as well. The animation is super cute when standing on an obstacle, and it looks like I'm happily skipping along as I'm moving through the world! The music is well synced--I feel like all of the actions that didn't register were reasonable, and I like the differentiation between "you timed correctly but on the wrong beat to move that direction" (wrong beat) vs "you're bad" (miss) :)
A minor bug in selecting level and song: the click box for the Lake in level select seems to extend over the "orial" part of "Tutorial" (this shape seems similar for the Tutorial clickbox too, but less of a problem because there's nothing else to click over there). The song slelection also moves to the next song down before fully leaving the choice above.
Overall, amazing game. Thoroughly enjoyed!